Histamine intolerance and reduced DAO levels can lead to allergy-like symptoms, including: Skin problems such as rashes, itching, hives, flushing, eczema, psoriasis, and even acne [ 6]

The most common symptoms of histamine intolerance include: Migraine headaches Digestive symptoms, such as diarrhea Flushed skin Hives or an itchy skin rash Worsening eczema, or a condition that causes itchy and flaky rashes

The list of potential histamine intolerance symptoms is long, but some of the most common are related to the cardiovascular system, Dr. Kalika says. These include: Flushing, difficulty regulating body temperature, sudden excessive sweating Hives, rashes, swelling, itchy skin, eczema Racing heart, palpitations, arrhythmia

The digestive system and the brain are connected via something we refer to as “the gut-brain axis.” This means something that starts in the gut can spread to the nervous system, causing symptoms in the brain, such as headaches, anxiety, and Similarly, histamine reactions can also spread to your skin, causing a rash, such as hives.